1. Field of the Invention
This invention relates to railroad car couplers. More particularly, this invention relates to a tail portion of a knuckle of the coupler having a configuration which interacts with a lock of the coupler in such a manner that upon the knuckle being swung from an open position to a closed position, the lock drops to prevent the knuckle from opening thereafter.
2. Description of the Prior Art
Standard AAR (Association of American Railroads) Type E couplers comprise a coupler head having therein a vertical lock chamber. Within the chamber is a coupler lock which may be selectively raised from a lower locking position to either one of two raised unlocking positions by a lock lift assembly which is attached to a lower leg portion of the lock.
The first unlocking position is known as lockset which allows a knuckle of the coupler to swing from the closed position to the open position during, for example, an uncoupling operation from an attached railroad car. The second unlocking position is known as knuckle throw. In this position, the lock is raised above the lockset position to engage and rotate a knuckle thrower which in turn pivots the knuckle to the open position.
When the knuckle is open, a fulcrum portion of the lock rests on a tail portion of the knuckle and is supported thereby. As the knuckle swings from the open position to the closed position, the knuckle tail portion slides under the fulcrum lock portion. When the knuckle reaches the closed position the lock drops to the locking position. Knuckle closing occurs, for example during the coupling of two railroad cars, and upon completion, the cars are fixedly joined since the knuckle of each coupler is closed and locked.
During the closing swing of the knuckle, interaction between the knuckle tail and the leg portion of the coupler lock, however, may produce undesirable results. On occasion, the lock fails to drop into the locking position upon the knuckle being closed because the lock has been inadvertently placed in the lockset position by contact between the knuckle tail portion and the leg portion of the lock.